remove_job() deletes the job from cron/jobs.json but leaves the per-job
output directory at ~/.hermes/cron/output/{job_id}/ behind. Over time
this accumulates orphaned dirs that never get reclaimed.
Adopted from #13510 by @hekaru-agent; the honcho RLock half of that PR
was already salvaged in commit dad021745 so this lands the remaining
cron cleanup hunk on its own.